Various electrical circuits, such as filters, circulators and correlators, employ transistors that are controlled to operate as switches. These circuits typically use switched filter elements as building blocks implemented by silicon Complementary Metal Oxide Semiconductor (CMOS) technologies. However, some CMOS dies may have difficulty in handling power levels greater than 10 mW at high frequencies (e.g. over 100 MHz) without becoming nonlinear or breaking down because CMOS transistors have low breakdown voltages. Accordingly, CMOS transistors may require either extra space for an additional device or a number of stacked devices to avoid breakdown under high drive levels.
Gallium Nitride (GaN) HEMT has attracted attention due to its high-power performance coupled with high breakdown voltage (e.g. over 40V). GaN HEMTs enable to handle high power in switching applications. For high power switching operation of a GaN HEMT, a gate choke resistor is typically used to prevent turning on a Schottky diode of the GaN transistor gate under a high voltage swing of the drain and source of the GaN HEMT. However, such gate choke resistance may cause RC time delay to the gate of the GaN HEMT, collapse a desirable rectangular pulse-shape of the gate control signal, and force to lower the speed of a control signal by a MHz order.
Some conventional GaN filters use benchtop optical line drivers to shift the CMOS voltages, input to the GaN filter, to a level necessary to handle higher input powers (e.g. over 100 mW). However, such optical line drivers may be limited to narrow voltage swings (e.g. 0-6V) and may not allow for adjustment of absolute voltage levels.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present disclosure as set forth in the remainder of the present disclosure.